Mates

[ormadorm]

I am bringing several subasemblies into a larger assembly and I would like to be able to move the various parts with respect to each other. I have several gear mates as well as concentric and coincident mates. My problem is this: I can bring in the subassembly and mate it just fine, but as soon as I change it from a rigid to a flexible assembly, the gear mates act up and throw all kinds of errors. What can I do? I've tried re mating the whole thing (sub and high end assembly) using good mating practices but it didn't seem to help.

 

[ormadorm]

Just to clarify, all the mates work great in the subassembly. But as soon as I bring it into the large assembly and make it flexible, the mates (especially the gear mates) have a hard time.

 

[Eltron]

Sometimes subassys just give you fits for no reason. Often it will end up being easier driving your movement with configurations.

Dan

http://www.eltronresearch.com

Dan's Blog

 

[Updraft]

Some of those special mates, such as gear mates, don't always behave as we might think. If your two gears are in the same subassy then the gear mate should also reside in that subassy. Mating the two gears in the next level assy should work, but has problems. I have found that gear mates and limit mates are strange this way.

- - -Updraft

 

[ormadorm]

Thanks for the input. I'll give those things a try.

 

[steinmini]

I have the same problem, but not with gears. I use rod ends on the end of the swinging arms, and even though it appears to be fine up to a certain level of definition, once I add the consequently last mate relation, it turns the under defined assembly into an over defined assembly and I get multiple errors. Once I delete the last mate, the assembly refuses to rebuild properly and many of the mates that were just fine before the last one was added, turn up with warning signs... Nothing helps except for deleting all highlighted mates and do it all over again. Frustrating... I would also say that I tried different ways to mate the components (changing the order of the way the assembly is built, but it happens again and again. The problem is that if I don't add some of the mates that are supposed to keep the parts together, any movement on the flexible parts (sub-assemblies) blows my assembly into unpredictable and weird positions... What am I missing?

 

[debodine]

I have no idea if this will help in your specific case (I have never faced that specific case), but the attached has helped me with mates in the past.

 

[debodine]

I should have added, on page 4 paragraph 4 (in "The 3-2-1 Method" discussion) is the paragraph that made me think of your situation when it talked about large assemblies with moving parts. I hope it helps.

 

[steinmini]

Thanks for the reading, I'll see if I've missed something from it. Solidworks is just a fine tool to work with until it starts acting in some aspects the other way around. That wouldn't be a problem If I could figure out what did I do the wrong way...

 

[steinmini]

Yup... that is what happens to me because I'm prototyping...

"And if these two different paths come up with slightly different answers, even to within 20 or 30 millionths of an inch, the Mate solver will flag the entire system as inconsistent."

 

[steinmini]

And guess what. Just opened the "problematic" assembly loaded with mating errors. It appears that after closing it and reopening it, all the errors disappeared. During opening, SW didn't even bother to ask me to rebuild it... Strange...